US4360658A
Expired / Lapsed
US
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Copolyester derived from terephthalic acid, phenylhydroquinone and hydroquinone
Assignee: Eastman Chemical Co
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Filing: 1981-02-23
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Granted: 1982-11-23
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Expires: 2001-02-23
Abstract
Abstract Copolyesters of terephthalic acid, phenylhydroquinone and 25 to 50 mole percent hydroquinone based on total moles of diol. These copolyesters are characterized by unexpected chemical resistance.
Inventors
- 👤 Winston J. Jackson, Jr.
- 👤 Herbert F. Kuhfuss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:21
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/16; C08G63/18; C08G63/19
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
50 words
Copolyester having a film- and fiber-forming molecular weight consisting essentially of the following divalent radicals ##STR2## wherein (B) is present in the amount of 50 to 75 mole percent and (C) is present in the amount of 25 to 50 mole percent based on total moles of (B) and (C).
Claim 2
Dependent Claim
50 words
Copolyester having a film- and fiber-forming molecular weight consisting essentially of the following divalent radicals ##STR2## wherein (B) is present in the amount of 50 to 75 mole percent and (C) is present in the amount of 25 to 50 mole percent based on total moles of (B) and (C).
Claim 3
Dependent Claim
35 words
Copolyester of claim 1 wherein (B) is present in the amount of 65 to 60 mole percent and (C) is present in the amount of 35 to 40 mole percent based on (B) and (C).
Claim 4
Dependent Claim
8 words
Shaped article of a copolyester of claim 1.
Claim 5
Dependent Claim
8 words
Shaped article of a copolyester of claim 2.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-22 | 1986-05-24 | 1986-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-22 | 1990-05-24 | 1990-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-22 | 1994-05-24 | 1994-11-23 | $7700.00 | Window Closed / Lapsed |